Selectively evacuated temperature regulated container



April 24, 1951 M. CLAR SELECTIVELY EVACUATED TEMPERATURE REGULATEDCONTAINER 7 Slieets-Sheet 1 Filed Aug. 8, 1946 INVENTOR. 1'10 TTEL CL HEBY fidWm/W TTORA/EY.

M. 'CLAR April 24, 1951 SELECTIVELY EVACUATED TEMPERATURE REGULATEDCONTAINER 7 Sheet s-Sheet 2 Filed Aug. 8, 1946 JTYg ZiS.

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M. CLAR 2,550,040 SELECTIVELY EVACUATED TEMPERATURE REGULATED CONTAINERApril 24, 1951 '7 Sheefc s-Sheet 3 Filed Aug. 8, 1946I///////I/I///////I INVENTOR. MOTTEL CLfl/e BY A4 M. CLAR April 24, 1951SELECTIVELY EVACUATED TEMPERATURE REGULATED CONTAINER 7 Sheets-Sheet 4Filed Aug. 8, 1946 M. CLAR April 24, 1951 SELECTIVELY EVACUATEDTEMPERATURE REGULATED CONTAINER 7 Sheets-Sheet 5 Filed Aug. 8, 1946INVENTOR J I OTTEL CLFl/E flTT NEY.

April 24, 1951 M. CLAR 2,550,040

SELECTIVELY EVACUATED TEMPERATURE REGULATED CONTAINER Filed Aug. 8, 19467 Sheets-Sheet 6 INVENTOR. M0 TTEL C1. A2

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April 24, 1951 cum 7 2,550,040

SELECTIVELY EVACUATED TEMPERATURE REGULATED CONTAINER Filed Aug. 8, 19467,Sheets-Sheet 7 1 I I l INVENTOE.

a Morn-L 'CLHE HTTORNEX Patented Apr. 24, 1951 UNITED STATES PATENTOFFICE SELECTIVELY EVACUATED TEMPERATURE REGULATED CONTAINER .MottelClar, Culver City, Calif.

Application August 8, 1946, Serial No. 689,290

'4 Claims. 1

This invention relates to storage and shipping containers oi novelconstruction and operation, to an improved method of preserving andtransporting perishable goods such as food products and to variousintegral features of construction which contribute to the particulareffectiveness of my containers.

It is an object of the invention to provide a food container "havingmeans for regulating the temperature of the products stored therein suchas by circulation of heated and cooled air, and further having a vacuumcompartment which may either be the storage chamber or may surround thestorage chamber to serve as an insulating space therefor. In "oneembodiment, my container is provided with means for selectivelyevacuating either the storage chamber 'or the surrounding insulatingspace, and also with means for circulating air through whichever ofthese spaces is not evacuated, so that the environment of the storedarticles may be adapted --to the particular product as well as adjustedin relation "to the external conditions or temperature of the region inwhich they are stored or through which they are being transported.

Another purpose is to provide a container of the character describedwhich is constructed of hollow dem'ountable panels which may beassembled, for example, as the lining of a rail-road car, aircraft,automotive truck, cargo vessel or, again, may be assembled anddismounted in a warehouse or other storage "space as needed from time totime.

A further obii'ect is the provision of a reusable container of thecharacter described which has no protruding attachments or parts so thata number of such units may be quickly and comactly stacked or lodged ina storageor shipping space, and in this connection there is provided anovel coupling assembly or high speed union for quickly connecting anddisconnecting "the container to suitable external means for evacuatingand/or circulating heated or cooled air through the several closedspaces as required.

An additional purpose is to :provide a container oi the characterdescribed wherein the several principal walls are effectively insulatedfrom each other as well as from conduits necessarily penetrating thewalls.

:Still another object is the provision of :a container of the characterdescribed which is provided with a hollow door or closure which may beevacuated simultaneously with an insulating space of the container;another feature is a floating :hinge construction which permits a more 2exact and airtight alignment of the door in "the door-Way; still anotherfeature is the provision of a door locking device particularly "adaptedfor a storage chamber of the present type.

Other objects and advantages of the invention will be apparent from thefollowing description and claims, the novelty'consisting in the featuresof construction, combination of parts, the unique relations of themembers and the relative "proportion-ing, disposition, and operationthereof, 'all'as more completely outlined herein and particularlypointed out in the appended claims.

Inthe drawings, which form part of the present specification Figure 1 isa longitudinal-vertical sectional view through my storage chamber;

Figure 2 is a perspective view of my storage chamber as seen from above;

Figure 3 is a slightly enlarged fragmentary lateral sectional view takenthrough the container along the line '3--3 of Figure 1';

Figure '4 is an elevational view of the back of the container showingthe door leading to the "internal control panel where externalair andvacuum lines are connectedto service the unit;

Figure 5 is a fragmentary sectional view taken along the line -'5-5 inFigure '4, showing the door handle in side elevation;

Figure '6 is a fragmentary sectional view taken through the innerchamber along the line 6-'fi of Figure 4 and showing the vacuum linehorizontally disposed along the inner chamber wall;

Figure '7 "is 'a front elevational View of a modified form of my storagechamber with the door p Figure 8 is an elevational view of one form ofcontainer door;

Figure 9 is -a sectional view through the doorlocking mechanism takenalong the line as of Figure 8;

Figure 10 is an elevational view of a housing assembly employed toanchor and insulate "condu-its which pass through the walls of mycontainers;

Figure 11 is an axial sectional view through a conduit mounted in thehousing of Figure 10 between two walls of a container;

Figure 12 is an axial sectional view taken through a conduit mounted inthe housing 'assembly of Figure 10, showing the manner in'which theconduit passes through three walls of the container which are spacedapart and insulated from one another;

Figure 13 is a fragmentary sectional view taken along the line l3--'|'3of Figure 14, showing the method of connecting a support between theinner walls of the container:

Figure 14 shows another modified form of my container illustrated inconnection with a schematic layout of associated refrigerating, heatingand evacuating apparatus;

Figure 15 is a vertical section taken through the rear wall of thecontainer of Figure 7;

Figures 16 and 17 are elevational views of the end of the refrigerationcoil housing of Figure 15, showing the split housing cover in closed andopen positions, respectively;

Figure 18 is an enlarged fragmentary sectional view taken along the linel8l8 in Figure 15, showing the vacuum line and the manner in which it iscarried through the chamber walls;

Figure 19 is an enlarged fragmentary view, in elevation, of the hingeddoor of Figure 14, showing the hinge mounting and the flexible conduitjoining the interior of the hollow door to the evacuated wall of thecontainer body;

Figure 20 is a fragmentary sectional view through the door of thecontainer of Figure '7, taken along the axis of a locking rod andshowing the arrangement of the locking wedge thereof;

Figure 21 is an elevational view, partially broken away, of the floatinghinge assembly of Figure 19 with the hinge plate removed;

Figure 22 is a sectional view of the floating hinge taken along the line22-22 of Figure 21;

Figure 23 is a sectional view taken along the line 2323 of Figure 19,showing the arrangement of the flexible vacuum conduit between the doorand the container;

Figure 24 is a side elevational view of my quickdetachable couplingassembly;

Figure 25 is a side elevational view of a modified form of the collar ofmy coupling assembly; I Figure 26 is a longitudinal sectional view takenthrough the assembly of Figure 24; V Figure 27 is a transverse sectionalView taken along the line 21-21 of Figure 24;

Figure 28 is a transverse sectional view taken through a wall of mycontainer constructed of collapsible panels, particularly showing theinterlocking edge construction of pairs of both insulating and hollowpanels; I

Figure 29 is a sectional view taken alon the line 29-29 in Figure 28through the locking edges of the hollow panels;

Figure 30 is a perspective view of an edge of one of the hollowinterlocking panels of Figure 29; and

Figure 31 is a partially sectioned enlarged detail of the liquidinjector of Figure 14.

' Figure 32 is a 'fragmental vertical sectional view taken thru thestorage chamber of Figure 1, showing an additional pair of lines, 80aand 82a, for circulating heated and cooled air thru the innermostcontainer 44. Figure 33 is a partial vertical sectional view taken' thruthe container of Figure 14 showin the hot and cool air conduits providedwith valve means for directing the respective air flow thru the storagespace, the surrounding insulating chamber, or both.

Ligure 34 is an enlarged sectional view taken thru the valve means ofFigure 33.

I'; has been found that many articles of food may be better preservedduring shipping and storage by use of a vacuum, either alone or inassociation with temperature control of the perishable article By thismeans the necessity, for example, of freezing foodstuffs for futuredistribution may be obviated and a more palatable product obtained asWell, since vacuum preservation does not change the character of organictissues; destroy vitamins or flavors, or remove minerals. However, useof my containers to obtain below freezing temperatures is alsocontemplated.

Further, a vacuum has a high insulating value so that its employmentjointly with heating or cooling means permits the maintenance of a moreuniform temperature within a container, which is valuable whether or notthe perishable items are stored in the evacuated section or not. Sincethe optimum environment for preservation of foods and beverages ofcourse differs widely from one article to another, the desired treatmentafforded different items necessarily differs and consequently I haveprovided containers with diverse arrangements of heated, refrigerated,and evacuated storage spaces therein.

Thus, for example, potatoes which are being shipped through freezingterritory would be carried in a heated chamber, while fish and meatcould be maintained at below freezing temperatures. Again, a rarified orevacuated atmosphere maintained at above freezing temperature isparticularly advantageous for the shipping of ripe, freshly pickedfruits and berries.

As shown in Figure 1, there is provided a generally rectangular shippingand storage container 40, within which are nested an intermediatecontainer 42 and a central food receptacle 44, each of the threecontainers having a door or entrance 43, 48 and 58 at the same end sothat entrance to the innermost receptacle is gained throughthe-successive doors.

The inner containers are spaced apart along their sides, top and bottomby a series of laterally spaced, non-metallic or insulating,longitudinal rails, 52 and 54, located between the respectivecompartments, each rail containing a series of lateral apertures 56 toallow passage of air therethrough, the individual rails having their topand bottom edges disposed in correspondin channels 51 formed in pairs ofoppositely aligned supports 58 which are mounted along the adjacentcontainer walls or may be formed integral therewith. The supports serveboth to restrain the rails against lateral movement and to facilitateinsertion of the successive inner containers within the outer ones. Acorrespondingly positioned series of skids 60 are additionally providedon the bottom of the outer container for ease in moving the same about afloor or the like.

Evacuation of air from food container 44 is efiected by a vacuum line62, connected to an external vacuum pump (not shown) and controlled byan automatic pressure or vacuum switch in communication with the chamberby conduit 64. These lines, together with a Water injector 66 andthermostat 68 enter the storage chamber through an insulating block 69mounted along the back wall thereof. The inner ends of the members 62,64, 66, and 68 are protected against contact with articles stored withinthe chamber by a perforated cover plate Hi. The vacuum line 62 mayextend horizontally along the end and side walls of the chamber as shownin Figure 6 to serve also as a guard or bumper for the Walls, beingprovided with successive openings 63 to permit evacuation of air, suchopenings bein spaced so that if one or more becomes clogged by thepressure of an article against it, the others will still permit the lineto function.

Intermediate container 42 is also penetrated with :a vacuum line 12 andvacuum gauge 274 as well .as :a pair of conduits l-'6 and 1.8 forcirculating hot .or cold air through the chamber in response to thethermostatic control 68. .Asimilar pair of air conduits 8i and 82 (whichmay also be responsive to thermostat 68) are .provided for the outermostchamber, being disposed to penetrate a transverse insulating wall 84disposed between containers 4i] and 42 .so as to separate the main airspace st of the outer chamber from a rear chamber portion 83 thereof,within which rear portion the various conduits maybe coupledifrom timeto time with externally extending lines .as described hereafter. .Accessto control chamber 88 is by way of an inverted 1L-shaped closure 90,hinged to the outer container 48 by recessed hinges 92 and provided with:a suitabl recessed catch to engage the top of the container at '94.Aipair of similar catches 95 are lilcewise mounted on the front closure'45. .In addition 'to the :insulating 'eifect obtained :by the :airspace 96 between the two inner, spaced containers, and that of outer airspaces 85 and 88, further insulation against heat transfer is obtainedthrough the use of insulating material 92 such as asbestos, pumice,fiber glass, sawdust, cork, .etc.,'which fills the hollow walls of theouter shell 40.

For use in moving the container, a handle 1927 (Figures 45) :is providedat either end thereof, sunk within a recess 192 so as to .lie beneaththe outer surface of the container wall, said handle being provided withan outwardly extending, engaging lug i I34 on either side thereof, sodisposed as to abut against the face of the recess when the handle hasbeen partly lifted, thereby avoiding crushing the fingers of the personslifting it, as might otherwise happen if the handle were allowed to comeup all the way.

Each of the inner compartments 42 and 44 is provided at its front-endwith an outwardly projecting flange 5B6 peripherally disposed about theaperture of the chamber, each flange having a groove I98 about its innerface adapted to be engaged by a plurality of locking wedges H mounted onthe outer face of the door 68 or 52!, so as to project beyond each edgethereof. Each of the locking wedges is 'disposedto move within a fixedguide collar H l, and i extended or retracted by means of :an operatingwheel H2 terminally mounted upon :a threaded shaft H4 which in turn isjournalled within .a centrally located, generally rectangular frame H6located on the outer face .of the door, said :shaft being threaded alsothrough the tapped aperture of a square-ended actuating tblock H8, whichis contained within the frame. The block or coupling .8 is restrainedagainst rotary movement by four :bell cranks, :each having a short arml2il which extends into a corresponding recess formed in the adjacentside of the block. Each of the bell cranks is pivotally supported at I26on :a bracket I28 formed on the inner surface of the housing H6 and hasa long arm I22 extending generally parallel to the axis of the screwA44. The arms 122 are connected at their outer :ends to radiallyextending, slidably'supported locking arms Hi9 having wedge blocks H0 attheir outer ends which engage the peripheral groove ills 'in the flangem to draw the door tightly against the doorway. By this construction,rotation of the operating wheel H12, causes the block M8 to travel up ordown :along theshaft I i-4 as the case may be, causing each lever :armI22 to slide its corresponding locking wedge I II] in .or out of theperipheral groove H18. In the alternative, the.

locking arms may be positioned :on the inner face of a door as in Figure20, each wedge Ilfla engaging :a correspondingly aligned stop or .flangei129. Compressible Ke. g. rubber) gaskets 32 are arranged about the dooredges.

The several conduits which pass through the walls are enclosed thereinby insulating housing 69. Although the conduits are depicted in Figure 1as vertically spaced within the housing, the latter may conveniently behorizontally disposed as shown in Figure 10. As seen particularly inFigure .11, such a block is formed of a main .body of non-metallic orinsulating material 152 (for example, molded plastic) carrying atransverse conduit section I 54 to which a'pipe or similarattachment maybe screw-threadedly attached. The chamber walls (42 and 44) are anchoredto the block I52 by screws I56 which-also'engage a (cork or rubber)gasket I55 and a metallic reinforcing ring I59 peripherally mounted onthe sirably formedin'several pieces for easy assembly, -as shown inFigure 12, and an outer .cover 151 may be molded integral therewith andprovided with suitable openings L58 through which screws secure theouter wall to the housing.

In order to quickly connect and disconnect the several conduits enteringthe chamber, .to the corresponding external vacuum orzair lines, thereis provided a novel coupling assembly, Figures fi l-27, consistingessentially of a blunt-ended, inwardly sloping conduit terminus section220 adapted to have its end wedged against a zoomplementary obtuse,annular face 222 of .:a hose or pipe-end 224 by action of anindependently :ro-

tatable collar 226 possessing an inwardly projecting flange 22'! whichis adapted to be brought into registration with the .back of theoutwardly extending annular face 222, said collar being designed toencircle jointly the ends of the conduit terminus 220 and pipe-end 224and draw. the two together by reason of engagement of a pair of inwardlyslanted bayonet :sloits 228 (formed on either side of the collar), witha pair of radially projecting studs L230 mounted on opposite sides ofthe conduit terminus. In order to lock the opposite pipe and conduitmembers .in this tightly engaged position, there is provided on theconduit terminus 22%} an outwardly extending annular flange 23! having aseries :of .closely placed, radially alignednotches .232 adapted to beengaged by a latch 234 'swinginglytmounted .on a radially extendinghandle 2% of .the collar. In aimo'dified form of collar shown in Figure25, instead of a handle, there is provided a generally annular neckformed integral with the body 5.2 26 and having an outer polygonal face240 adapted to be engaged by a suitable wrench in order to elfe'ctrotation of the collar.

A modified form of my storage container is illustrated in Figures 7 and15-18, this embodiment providing a vacuum storage container 242 disposedwithin a surrounding storage chamber 244, the temperature of the air inthe latter being regulated by a refrigerating or cooling unit 245 and .aheating unit 248, each of which latter are bolted onto the back of thecontainer and situated in a generally cylindrical external housing, 249and 250 respectively, similarly attached to the back of the container.This particular location of the heating and cooling units is notspecifi'ed by way of limitation however, since theseunits maybe locatedelsewhere within the con-" tainer as desired.

A split cover plate is provided for the outer ends of the cylindricalhousings 249 and 250, the upper plate I90 (Figures 16 and 17) havinga'pair of pipe-receiving openings I88 formed along its inner edges aswell as a pair of laterally spaced slots I92 and correspondingly shapedpair of ears I94 adapted to be received therein and held in suchalignment by a latch I96 and pin I91.

Vacuum line I54a. is adapted to evacuate either the vacuum chamber 242or the insulating space I91 which surrounds both the vacuum storagechamber 242 and the heated and cooled storage chamber 244, the lineserving further to evacuate hollow door 252 through a flexible conduitas will be shortly described. The manner of carrying the vacuum linethrough the pair of container walls is shown in Figure 18, there beingprovided an externally threaded plug 254 formed of insulating materialand adapted to receive the vacuum line through its center and toscrewthreadedly engage a corresponding aperture in the outer containerwall 256 so that upon insertion therein it will act to compact anannular plug 258 formed of compressible insulating material (for examplerubber) surrounding the conduit and having its opposite face in abutmentagainst inner insulating wall 250.

Inner walls 260 and 262 are held in spaced relation by means of lateralsupports I64 which are secured to each adjacent wall by a bolt I68(Figure 13) said supports being at the same time held from.direct'contact'with either the wall or the'bolts by means of a flatinsulating washer I12 disposed on one side of the support, and on theopposite side by an insulating sleeve I14 having a terminal, outwardlyflanged flat portion I15 adapted to be sandwiched between the twomembers. Thus, it will be seen that the container walls, supports andconduits may be formed of metal to insure strength but are restrainedfrom heat conducting, metal-to-metal contact by such structures as theinsulating rails 52 and 54, the conduit housing block 69, the endinsulating walls 84, the lateral support mountings I12 and I15, and theinsulating structures of Figure 18.

Another modification of my container is illustrated .in Figures 14, 19and 21-23, the container 40a being provided with an outwardly slopingdoorway and a correspondingly wedge-shaped hollow door 460: which seatstherein. One hinge plate I is attached to the sloping edge of the doorin the conventional manner while its companionate hinge plate 132 issecured by suitable screws to a horizontally slidable block I34,normally urged to one side by a pair of coil springs I36 which are heldin alignment therewith by a corresponding pair of centering pins I38extending from the side of said block so as to form a partial core foreach coil spring. The sliding block and springs are in turn retainedwithin a recess in the sloping doorway by means of a cover plate I40having a pair of horizontal slots I42 to permit passage of screws I44which connect the hinge plate I82 to the sliding blocks. By thisarrangement there is obtained a highly effective automatic centering ofthe inwardly slanted edges of the door within its sloping doorway asextension of the locking wedges IIO thus serves to force it intoairtight alignment.

A further feature of the present construction is the provision of ahollow chamber within the door panel 46a which may be evacuated togetherwith a vacuum chamber of the container, and to effectuate this, aflexible conduit I46 is provided to connect the door chamber with thebody chamber, said conduit being adapted to lie in its collapsedposition (that is, when the door is closed) within a complementary pairof corresponding recesses I48 and I50 formed respectively along thehinge edge of the door and the adjacent face of the container. A similarattachment is also provided between the hollow door 252 and the vacuumchamber I91 of the container of Figures 7 and 15'. A vacuum releasevalve I5I is also present on the several vacuum doors in order to permitentry of air to the inner chambers so as to facilitate opening the doorsthereof.

A somewhat schematic arrangement of elements adapted to service my foodcontainers is also shown in Figure 14;, there being provided a vacuumpump I98 responsive to automatic pressure switch I99, a heating coil 290and a cooling unit composed of compressor 202 and condenser tubes 294and evaporator tubes 205 for vaporization of liquified ammonia or otherrefrigerant. Air which has been warmed or cooled is circulated throughconduits 82 and by electrically driven fans 206 and 208 respectively,the heating and cooling systems both being operated by thermostaticcontrol 20l. Eachair conduit 88 and 82 contains a shut-off or damper 8Iand 83 respectively, by means of which the air coming out of the chamberis by-passed around the heating or cooling unit as the case maybe, thuspreventing, for example, exposure of air-cooling tube 205 to warm airmoving out through conduit 80. An atomizer member 2I4 (Figure 31) isadditionally provided for injecting water or other liquid into the foodstorage chamber from time to time in order to maintain the moisturecontent thereof or to supply a preservative spray as desired. Since theheating and refrigerating units as well as the atomizer, pressure switchand thermostatic control are of conventional design they will not bedescribed in detail.

By still another modification, my vacuum container may be constructedfrom demountable interlocking panels (Figures 28-30). connected hollowpanels I15 is sandwiched between outer panels I16 formed of insulatingmaterial, and the storage chamber thus formed and/or the hollow sectionsof the connected panels I15 may be evacuated or, in the alternativesupplied with cooled or heated air as in the earlier described forms.The hollow panels are constructed with a longitudinal lip I18 eX-tending along an edge and arranged to overlie a complementary lip I19 ofthe adjoining panel, the lips being provided respectively with male I11and female I80 guide members, designed to snugly engage each other andpermit circulation or evacuation of air through passageways I83 whichthus join the interiors of adjacent panels. The lips I18 and I19 areheld in frictional engagement by screws inserted jointly throughtransverse, aligned channels I8I and I82 formed by cylindrical walls inthe respective lips, the former channel being internally threaded, itbeing observed that both channels are open at either end but are at noplace in communication with the hollow or vacuum sections of theirpanels. Analogous lip sections of the insulating panels I16 arestrengthened by insertion therein of U-' shaped sleeves or braces I84and are fastened together by suitable screws I86 therethrough.

While I have shown and described in some detail some presently preferredembodiments of my A lining of vacuum container, it is to be understoodthat various modifications may be made in the construction and operationthereof within the scope of the subsequently claimed invention.

The invention claimed is:

1. A container for preserving perishable goods including: a plurality ofnested chambers each with its own closure, said chambers being spacedapart to form closed insulating space therebetween, the innermost ofsaid chambers being adapted for use as a storage chamber and at leastone of said chambers having an inwardly tapered wall forming an entrancethereto; a closure for said chamber having a complementary tapered walladapted to frictionally engage the tapered wall of said chamber; a hingeassembly having one hinge plate secured to each of said tapered wallsand adapted to lie in juxtaposition when the door is closed, one of saidplates being adapted for limited movement along said tapered wall so asto permit self alignment of the closure Within said chamber entrance;locking means on said closure adapted to draw the same tightly againstsaid closure entrance; means for selectively evacuating said storagechamber and said insulating space; and means adapted to circulate cooledor heated air selectively through said storage chamber and saidinsulating space.

2. A container for preserving perishable goods including: a plurality ofnested chambers spaced apart to form a closed insulating spacetherebetween, at least one of said chambers being adapted for use as astorage chamber; means for evacuating at least one of said chambers; andother means for circulating temperature-controlled air thru said otherchamber said last means being disposed, at least in part, within atubular housing detachably connected to the outermost chamber, whichhousing is provided with a split cover plate formed with pipe receivingopenings along its intersection and having looking means therefor, andcorresponding projecting lugs and aligning slots formed along saidintersection.

3. A container for preserving perishable goods including: a plurality ofnested chambers each with its own closure and spaced apart to formclosed insulating space between chambers, the innermost of said chambersbeing adapted for use as a storage chamber, longitudinal rails disposedbetween said nested chambers so as to space them apart, the rails beinglaterally separated from each other, provided with transverse aperturesto allow passage of air therebetween within the closed insulating space,and being retained in complementary channels formed along opposing facesof the walls of adjacent chambers, and coupling means carried by eachchamber for connection to external means adapted to evacuate and tocirculate cooled or heated air selectively through said storage chamberand said insulating space.

4. A container for preserving perishable goods including: a plurality ofnested chambers each with its own closure and spaced apart to formclosed insulating space between chambers, the innermost of said chambersbeing adapted for use as a storage chamber, coupling means carried byeach chamber for connection to external means adapted to evacuate and tocirculate cooled or heated air selectively through said storage chamberand said insulating space, the outermost chamber of which is providedwith longitudinally directed skid rails on its bottom and has a secondclosure adapted to give access to said coupling means carried by innernested chambers, and the innermost chamber is provided with a Vacuumconduit extending around its inner sides so as to serve as well as abumper guard for goods placed therein.

MOTTEL CLAR.

REFERENCES CITED The following references are of record in the:

file of this patent:

UNITED STATES PATENTS Number Name Date 450,373 Ott Apr. 14, 1891'.643,358 Konold Feb. 13, 1900 877,987 Deschane et a1 Feb. 4, 1908-1,054,578 Madison Feb. 25, 1913' 1,088,453 Roberts Feb. 24, 1914-1,253,065 Looze Jan. 8, 1918 1,475,838 Lamb Nov. 27, 1923 1,848,440Spitzenberger et a1. Mar. 8, 1932 1,859,613 Bailey May 24, 19321,873,838 Gebhard 1 Aug. 23, 1932' 1,948,587 Macready et al Feb. 27,1934: 2,000,467 Lindseth May 7, 1935' 2,000,882 Comstock May 7, 19352,071,175 Philipp Feb. 16, 1937 2,102,225 Russell et a1 Dec. 14, 19372,147,026 Glab Feb. 14, 1939 2,345,204 Lodwig Mar. 28, 1944- 2,425,816Maxson Aug. 19, 1947' FOREIGN PATENTS Number Country Date 4,612 GreatBritain Nov. 29, 1876 17,802 Australia Acc. June 13, 1935

